This section provides background information related to the present disclosure, which is not necessarily prior art.
Such a cooling unit is known, for example, from DE 10 2012 108 110 A1. The cooling unit may be designed as a wall-mounted or roof-mounted unit. Through an air inlet opening, air is routed from the interior of the switchgear cabinet to the inner circuit. The heated air from the interior of the switchgear cabinet passes through the heat exchanger designed as an air/coolant circuit in the inner circuit and is returned as cooled air via an air outlet opening to the interior of the switchgear cabinet. The outer circuit has another air inlet opening and another air outlet opening, by which surrounding air of the switchgear cabinet arrangement is routed into the outer circuit, through the air/coolant heat exchanger arranged in the outer circuit, and back to the surroundings via the air outlet opening.
For an effective heat exchange, it is necessary for the heat exchangers to be bathed as optimally as possible by the respective air. In turn, it is necessary for this that the respective air, before impinging on the respective heat exchanger, be deflected precisely in the respective air flow direction of the particular heat exchanger. Typical heat exchangers are often designed as sheetlike components, being dimensioned substantially flatter in the air flow direction than in the two spatial directions perpendicular to this. In cooling units designed as wall-mounted units, the heat exchanger is therefore often oriented, for space considerations, so that its air flow direction extends in the depth direction of the cooling unit, in order to limit the dimension of the cooling unit in the depth direction. But since the air inlet opening and the air outlet opening by which the inner circuit communicates with the interior of the switchgear cabinet and the outer circuit with the surroundings are arranged with a vertical offset relative to the particular heat exchanger, this orientation of the heat exchanger in relation to the air inlet and air outlet openings requires that the air admitted into the inner circuit and the outer circuit is routed effectively upstream from the air inlet side of the heat exchanger so that it can flow optimally through the heat exchanger.
Thus far, this has only been inadequately solved with the cooling units known in the prior art. Often the heat exchangers are placed at a slant in order to optimize the oncoming flow, although they are always still bathed in a flow at the side, which results in a strong gradient of air velocity across the air inlet side of the heat exchanger. Thus, local air velocity peaks are med, while other regions of the heat exchanger have little or no air flow passing through them. In the regions where air passes through the heat exchanger with especially high velocity gradient, this may result, for example, in condensate formed in the heat exchanger, for example on its fins, becoming detached and hurled into the interior of the switchgear cabinet, which is undesirable.
In order to prevent this transfer of water of condensation into the interior of the switchgear cabinet, it is provided for example in DE 10 2012 108 110 A1 to arrange the heat exchanger located in the inner circuit above the air outlet opening of the inner circuit, so that the detaching condensate can be taken away to a condensate collecting tray in the lower region of the inner circuit. But this, in turn, requires increased space to accommodate all the components of the unit.